A doctor from Banstead has admitted using a hidden camera to spy on patients in a long-running "sinister and indecent" campaign.

Lam Hoe Yeoh appeared at Croydon Crown Court on Tuesday, where he admitted seven counts of voyeurism, six counts of making an indecent photograph of a child and one of possessing extreme pornography.

The court was told Yeoh, 62, of Garratts Lane, filmed more than 1,000 victims over three years - including men, women and children who were patients, colleagues and visitors - and spliced the footage together to create compilation films.

However, the dirty doctor's habit was curtailed when he accidentally filmed himself while installing a hidden camera which fell from its location in the privately-run St Anthony's Hospital in North Cheam.

Prosecutor Peter Clement said the voyeurism charges, which relate to the period January 1 2011 to April 15 this year, included a handful of identifiable victims as well as 1,084 people whose identity was unknown.

He said the crimes were uncovered following "a single, discrete incident" at the private hospital in April this year.

Bestiality

Mr Clement said: "He visited a toilet block and went to a lavatory near the desk where two ladies had been working.

"Then he left. He had secreted a covert video recording device.

"The device fell from the position, when it was recovered by one of the two ladies.

"Examination that day showed the device had captured and recorded one of those ladies using the lavatory.

"But he [Yeoh] had inadvertently filmed himself securing that device. It was what the police found subsequently that gave rise to these offences."

Yeoh, who is also known by the first name Robin, was arrested at the hospital in April after an alleged victim contacted police.

The offences took place in a number of locations across the country, including Portland Hospital in central London and at medical facilities in Thames Ditton, Sutton and Exeter.

A hidden camera that fell from a toilet block at this hospital led to Yeoh's offending being uncovered

The court heard that he used a range of devices, including pen drives and watches, and that footage was found on both his home computer and his NHS work computer.

When police carried out searches following Yeoh's arrest, they discovered 22 covert cameras and several personal computers.

Mr Clement described the offending, involving victims as young as three, as "sophisticated, organised, planned and long-running".

One of the female victims had been secretly recorded 300 times.

The extreme pornography charge appeared to show acts of bestiality, the court was told.

Mr Clement said Yeoh "grossly abused" the high degree of trust placed in him.

He added: "The [voyeurism] offending was vast and beyond any previously investigated by the Metropolitan Police.

"His intention was sinister, indecent and criminal."

Yeoh was remanded in custody to be sentenced on Wednesday and was warned to expect a "significant" prison sentence